Showing posts with label cognitive. Show all posts
Showing posts with label cognitive. Show all posts

Saturday, June 16, 2012

Role of omega-3 in preventing cognitive decline in older people questioned

ScienceDaily (June 13, 2012) — Older people who take omega-3 fish oil supplements are probably not reducing their chances of losing cognitive function, according to a new Cochrane systematic review. Based on the available data from studies lasting up to 3.5 years, the researchers concluded that the supplements offered no benefits for cognitive health over placebo capsules or margarines, but that longer term effects are worth investigating.

See Also:Health & MedicineCholesterolDietary SupplementMind & BrainIntelligenceDementiaPlants & AnimalsFoodFishLiving WellReferenceOily fishSaturated fatUnsaturated fatOmega-3 fatty acid

Omega-3 fatty acids are fats responsible for many important jobs in the body. We get these fats through our daily diets and the three major omega-3 fats are: alpha linolenic acid (ALA) from sources such as nuts and seeds and eicosapentoic acid (EPA) and docosahexaenoic acid (DHA) from sources including oily fish such as salmon and mackerel. A number of studies have hinted that omega-3 fatty acids and DHA in particular may be involved in keeping nerve cells in the brain healthy into old age. However, there is limited evidence for the role of these fats in preventing cognitive decline and dementia.

The researchers, led by Emma Sydenham at the London School of Hygiene & Tropical Medicine (LSHTM), London, UK, gathered together evidence from three high quality trials comparing the effects of omega-3 fatty acids taken in capsules or margarine spread to those of sunflower oil, olive oil or regular margarine. A total of 3,536 people over the age of 60 took part in the trials, which lasted between six and 40 months. None of the participants had any signs of poor cognitive health or dementia at the start of the trials.

The researchers found no benefit of taking the omega-3 capsules or spread over placebo capsules or spread. Participants given omega-3 did not score better in standard mental state examinations or in memory and verbal fluency tests than those given placebo.

"From these studies, there doesn't appear to be any benefit for cognitive health for older people of taking omega-3 supplements," said Alan Dangour, a nutritionist at LSHTM and co-author of the report. "However, these were relatively short-term studies, so we saw very little deterioration in cognitive function in either the intervention groups or the control groups. It may take much longer to see any effect of these supplements."

The researchers conclude that the longer term effects of omega-3 fatty acids on cognitive decline and dementia need to be explored in further studies, particularly in people with low intakes of omega-3 fatty acids in their diet. In the meantime, they stress other potential health benefits. "Fish is an important part of a healthy diet and we would still support the recommendation to eat two portions a week, including one portion of oily fish," said Dangour.

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Tuesday, May 15, 2012

New nutrition bar improves metabolic biomarkers linked to cardiovascular disease, cognitive decline, and anti-oxidant defenses in only two weeks

ScienceDaily (May 10, 2012) — Scientists at Children's Hospital Oakland Research Institute's (CHORI) Nutrition & Metabolism Center, led by National Medal of Science winner Bruce N. Ames, PhD, have developed a low-calorie fruit-based high fiber vitamin and mineral nutrition bar called the "CHORI-bar" that improves biological indicators (increased HDL-c and glutathione, lowered homocysteine) linked to risk of cardiovascular disease, cognitive decline, and associated decline in anti-oxidant defenses.

See Also:Health & MedicineDiet and Weight LossNutritionMind & BrainDieting and Weight ControlNutrition ResearchPlants & AnimalsFoodVeterinary MedicineLiving WellReferenceFood groupsHealth benefits of teaLow-carb dietsDietary mineral

The CHORI-bar is intended to help restore optimal nutritional balance in people eating poor diets, and to help transition them to healthier eating habits. The bar is satiating and at only approximately 110 calories per bar, may be helpful in weight reduction programs.

The first research report on the CHORI-bar will appear in the August 2012 FASEB Journal (the Journal of the Federation of American Societies for Experimental Biology) published online on May 1, 2012.

Low intake of many vitamins and minerals is widespread in the U.S. After years of studying the interactions of vitamins and minerals with metabolic processes, Dr.Ames became convinced that modest deficiencies could be contributing to metabolic imbalances that increase risk of diseases associated with obesity and aging, such as diabetes, cancer, and heart disease. In 2006, he proposed the Triage Theory that provided a mechanistic rationale connecting modest vitamin/mineral deficiencies with disease (2), which was strongly supported by subsequent analyses (3,4).

In 2003, Dr. Ames and his colleague Mark Shigenaga, PhD, whose research focuses on the impact of food on gut function, embarked on the development of the CHORI-bar, an economical, low calorie, food supplement that could restore metabolic balance. Intestinal health is now widely recognized to be an important determinant of overall health. Food components that benefit gut health, such as certain soluble fibers and polyphenols, also deficient in typical Western diets, were included in the bar along with a number of other ingredients, all aimed at helping to restore optimal nutrition. Dr. Ames assembled a team of scientists and a collaboration was initiated with the Processed Foods Unit at the United States Department of Agriculture, Agricultural Research Service in Albany, Calif. to assist in the production of a tasty and nutritious bar.

Since the project began, a series of bar formulations were developed, and to date 11 small pilot trials were conducted to refine components and improve palatability from an almost inedible start to a tasty bar. Improvements are continuing to expand the number of disease risk biomarkers favorably impacted by the bar.

The FASEB Journal report describes the prototype bar developed in this program and presents results of a 2-week trial in 25 generally healthy adults led by CHORI-bar team member and pediatric cardiologist Michele Mietus-Snyder, MD. The participants varied in ages and BMI and ate two bars each day for 2-weeks. Included in the panel of assays at the beginning and end of the trial, in addition to standard measures of lipids, glucose metabolism, and inflammation, was ion mobility analysis (developed by CHORI Senior Scientist Ronald Krauss, MD, (5)) used to quantify lipoprotein sub-fractions, and a liquid chromatography linked tandem mass-spectrometry (LD/MS/MS) assay (developed by CHORI Associate Staff Scientist Jung Suh, MPH, PhD (6)) to measure thiol compounds and amino acid metabolites. This expanded panel of assays permitted a more in depth look at biomarkers and at clues to mechanisms underlying effects of the CHORI-bar.

Impressively, favorable metabolic changes occurred after only 2-weeks of bar intake, without guidelines as to whether to use the bar as a meal replacement or a supplement. For example, increased HDL cholesterol has been reported after intake of several individual bar ingredients, but at much higher doses than what is present in the bar. The possibility that bar ingredients are acting additively or synergistically is supported by some preliminary evidence.

Two examples from the results of this trial emphasize the fact that, with the right mixture of food components, pharmacological or supraphysiological doses are not needed to positively move metabolism in a healthy direction.

1) It is difficult to both raise HDL and lower homocysteine either pharmacologically or with dietary interventions. "Heart-healthy" diets most consistently linked to an increase in HDL-c are those that emphasize fat quality more than quantity, such as the Mediterranean diet. The CHORI-bar combines aspects of the Mediterranean diet with the most biologically active form of folate (5-methyl-tetrahydrofolate). The latter is expected to bypass the need for high levels of folate required to keep homocysteine at a healthy level in individuals with the TT MTHFR polymorphism, which is present in half the U.S. population.

2) Glutathione is the principal regulator of the cellular redox environment, and is important for preventing oxidative stress. Glutathione declines with age and is low in many diseases. Few drugs and only high doses of certain food constituents have been reported to raise glutathione, but only 2-weeks consumption of the bar was required.

Current research is continuing on several fronts. In addition to its potential to have an impact on public health, the CHORI-bar is a research tool that can elucidate mechanisms by which food components in the bar interact with metabolic pathways to favorably impact disease-relevant biomarkers. Two additional bars have been developed that expand the number of biomarkers improved by the bar to include measures of insulin resistance, inflammation, and additional elements of lipid metabolism, notably LDL cholesterol. Efforts are underway to combine attributes of all 3 bars in a single bar. A series of clinical trials have also been initiated that test the efficacy of the CHORI-bar in improving metabolism in individuals with diseases accompanied by metabolic dysregulation favorably impacted by the bar, including obesity, asthma, and hypertension. And finally, development of additional biomarker assays is underway to expand the classes of metabolic changes that can be detected, such as several different types of DNA damage.

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